1. Field of the Invention
The invention relates to neutral binuclear iridium (I) phosphine complexes of the general formula: ##STR3## in which X is fluorine, chlorine, bromine or iodine, and ##STR4## is in each case a chiral bidentate diphosphine ligand. The complexes have a quadratic-planar configuration at the iridium centers and can thus occur in two stereoisomeric forms (cis- and trans-form) if the diphosphine ligands do not have a C.sub.2 symmetry relationship between the two phosphorus atoms. In these cases, here and in the text below both stereoisomers are always intended, both in the pure form and also as a mixture.
The invention also relates to a process for the preparation of those complexes.
Furthermore, the invention relates to processes for the asymmetric hydroamination of olefins under catalysis by iridium (I) phosphine complexes of the formula I.
2. Background of the Invention
The asymmetric hydroamination of olefins is a potentially important method for preparing optically active amines. To date, however, only a few practical examples of this reaction are known; in particular, there is a lack of satisfactory processes for intermolecular hydroamination. The examples known to date are notable in particular for low activity of the catalysts used and correspondingly low reaction rates. In addition, the catalyst often only survives a few catalytic cycles, which renders the process unusable for industrial application.